1. Field of the Invention
The present invention relates to techniques for performing automated speech recognition and, more particularly, to techniques for removing personally identifying information from data used in human-assisted transcription services.
2. Related Art
It is desirable in many contexts to generate a written document based on human speech. In the legal profession, for example, transcriptionists transcribe testimony given in court proceedings and in depositions to produce a written transcript of the testimony. Similarly, in the medical profession, transcripts are produced of diagnoses, prognoses, prescriptions, and other information dictated by doctors and other medical professionals.
At first, transcription was performed solely by human transcriptionists who would listen to speech, either in real-time (i.e., in person by “taking dictation”) or by listening to a recording. One benefit of human transcriptionists is that they may have domain-specific knowledge, such as knowledge of medicine and medical terminology, which enables them to interpret ambiguities in speech and thereby to improve transcript accuracy.
It is common for hospitals and other healthcare institutions to outsource the task of transcribing medical reports to a Medical Transcription Service Organization (MTSO). For example, referring to FIG. 1, a diagram is shown of the typical dataflow in a conventional medical transcription system 100 using an outsourced MTSO. A physician 102 dictates notes 104 into a dictation device 106, such as a digital voice recorder, personal digital assistant (PDA), or a personal computer running dictation software. The dictation device 106 stores the spoken notes 104 in a digital audio file 108.
The audio file 108 is transmitted to a data server 110 at the MTSO. Note that if the dictation device 106 is a telephone, the audio file 108 need not be stored at the site of the physician 102. Rather, the telephone may transmit signals representing the notes 104 to the data server 110, which may generate and store the audio file 108 at the site of the MTSO data server 110.
The MTSO may interface to a hospital information system (HIS) database 112 which includes demographic information regarding, for example, the dictating physician 102 (such as his or her name, address, and specialty), the patient (such as his or her name, date of birth, and medical record number), and the encounter (such as a work type and name and address of a referring physician). Optionally, the MTSO data server 110 may match the audio file 108 with corresponding demographic information 114 from the HIS database 112 and transmit the audio file 108 and matched demographic information 114 to a medical transcriptionist (MT) 116. Various techniques are well-known for matching the audio file 108 with the demographic information 114. The dictation device 106 may, for example, store meta-data (such as the name of the physician 102 and/or patient) which may be used as a key into the database 112 to identify the corresponding demographic information 114.
The medical transcriptionist 116 may transcribe the audio file 108 (using the demographic information 114, if it is available, as an aid). The medical transcriptionist 116 transmits the report 118 back to the MTSO data server 110. Although not shown in FIG. 1, the draft report 118 may be verified and corrected by a second medical transcriptionist to produce a second draft report. The MTSO (through the data server 110 or some other means) transmits a final report 122 back to the physician 102, who may further edit the report 122.
Sensitive information about the patient (such as his or her name, history, and name/address of physician) may be contained within the notes 104, the audio file 108, the demographic information 114, the draft report 118, and the final report 122. As a result, increasingly stringent regulations have been developed to govern the handling of patient information in the context illustrated by FIG. 1. Even so, sensitive patient information may travel through many hands during the transcription process. For example, the audio file 108 and admission-discharge-transmission (ADT) information may be transferred from the physician 102 or HIS database 112 to the off-site MTSO data server 110. Although the primary MTSO data server 110 may be located within the U.S., an increasing percentage of data is forwarded from the primary data server 110 to a secondary data server (not shown) in another country such as India, Pakistan, or Indonesia, where non-U.S. persons may have access to sensitive patient information. Even if data are stored by the MTSO solely within the U.S., non-U.S. personnel of the MTSO may have remote access to the data. Furthermore, the audio file 108 may be distributed to several medical transcriptionists before the final report 122 is transmitted back to the physician 102. All sensitive patient information may be freely accessible to all handlers during the transcription process.
What is needed, therefore, are improved techniques for maintaining the privacy of patient information during the medical transcription process.